BACKGROUND In a previous study of gene array data, the authors identified survivin as a candidate marker of aggressiveness in clear cell renal cell carcinoma (ccRCC). What remained in question was whether survivin expression at the protein level is an independent predictor of disease progression and cancer-specific survival. METHODS Between 1990 and 1994, 312 patients underwent nephrectomy for ccRCC at Mayo Clinic Rochester and had paraffin tissue available. The authors performed immunohistochemistry with antisurvivin antibody, quantitated the expression by using an image-analysis system, and analyzed the association of survivin expression with disease progression and cancer-specific survival. RESULTS Within the cohort, 97 patients (31.1%) had high levels of survivin expression. Patients who had high survivin expression levels were at significantly increased risk of death from RCC compared with patients who had low expression levels (risk ratio [RR], 5.3; 95% confidence interval [95% CI], 3.5-7.9). The 5-year cancer-specific survival rate was 43.0% for patients with high survivin expression and 87.2% for patients with low survivin expression. In multivariate analysis, survivin expression remained associated with death from RCC even after adjusting for the Eastern Cooperative Oncology Group performance status; 2002 Tumor, Lymph Node, Metastases (TNM) stage groupings and nuclear grade (RR, 2.4; 95%CI, 1.5-3.8); and the Mayo Clinic composite TNM stage groupings, tumor size, nuclear grade, and tumor necrosis (SSIGN) score (RR, 1.8; 95%CI, 1.1-2.9). Among 273 patients who had localized ccRCC, survivin expression was associated significantly with cancer progression (RR, 3.9; 95%CI, 2.4-6.2). CONCLUSIONS Survivin expression is an independent predictor of ccRCC progression and death from RCC. Thus, survivin has the potential to offer additional prognostic information and to provide a novel target for the development of new adjuvant therapies.